1. Field of the Invention
The present invention relates generally to filter cleansing systems and, more specifically, to a high efficiency backflush filter apparatus that includes a bellows mounted on top of the filter screen.
2. Description of the Related Art
Filters are an essential component in most fluid flow systems. A wide variety of filter cleansing systems have been designed which allow the filter to be cleansed without removal of the filter from the system. One method of cleansing the filter in this manner is to backflush fluid through the filter to free the impurities from the filter and then allow the impurities to settle and be removed from the system. One way in which fluid is backflushed through a filter is by reversing the direction of the pump which is carrying the fluid through the system. In this type of a backflush system the backflush of fluid occurs at the same pressure as the suction of the fluid through the filter. Many times this pressure is insufficient to thoroughly cleanse the filter of impurities, thus resulting in an inefficient backflush. The inefficient design of the backflush system necessitates the use of small area filters which limits the overall flow through the filter.
Consequently there is a need for a system for efficiently cleansing a filter. The high efficiency backflush system for a filter should use a collapsible member to force fluid in a reverse direction through a filter element thereby flushing any impurities from the filter element. By using a collapsible member to force fluid through the filter element, the most effective backflush pressure may be achieved for any particular filter system design. The high efficiency backflush system for a filter should also be designed to prevent any suction of the removed particles back to the filter element after the backflush operation has flushed the filter element of impurities.
The following patent publications describe filter cleansing systems, but none of the following describe a filter cleansing system as effective as the present invention. None of the following patent publications describe a backflush system having the same structural elements and design simplicity as the present invention.
U.S. Pat. No. 3,278,034, issued on Oct. 11, 1966, to Robert E. West describes a washable swimming pool filter tank having a slide valve cylinder mounted concentrically within the filter tank and attached thereto in a permanent and completely leakproof manner.
U.S. Pat. No. 3,984,326, issued on Oct. 5, 1976, to Henry Bendel describes a gravity filtering equipment including a flushing device comprised of a movable bell to tightly enclose a compartment for backflush cleaning operation.
U.S. Pat. No. 4,486,307, issued on Dec. 4, 1984, to Walter Weiler describes a filter apparatus with a filter bed washing means comprised of a suction bell, the side walls of which define a compartment of the respective partial volume of the filter bed to be cleaned, which moves from one area of the filter bed to another.
U.S. Pat. No. 5,078,873, issued on Jan. 7, 1992, to Brent C. Black et al. describes a filter cleaning apparatus comprised of a moving hood sealed on a filtered compartment and using a pump to provide back flow for medium cleaning process.
United Kingdom Patent Application Number 7,550, published on Jan. 13, 1902, describes an improved filter arrangement designed to automatically actuate a reverse flow of liquid through the filter bed when the level of unfiltered liquid in the filter tank reaches a predetermined level.
German Patent Application Number 1,221,197, published on Jul. 21, 1966, and Soviet Union Patent Application Number 1,194,450 (A), published on Nov. 30, 1985, generally show filter backflush systems.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a high efficiency backflush system for a filter solving the aforementioned problems is desired.